Common video slot machines randomly select and display an array of symbols, using virtual reels, then grant an award to a player based on the occurrence of certain symbol combinations across paylines. Typically, the game ends after the symbols are displayed and the award, if any, is granted. Although these types of games are highly successful, it is advantageous to provide bonus games that occur once in a while to make the game more interesting to a player. The bonus games typically offer the potential for a high payout. A more interesting game will generate increased revenue to the casino by its increased play.
It is desirable to provide a bonus game that has the potential to award the player a large sum of money to attract the players to the machines; however, such large sums should only be awarded very infrequently. During a typical playing session, the player should experience the bonus game multiple times to maintain player interest in the machine. It is therefore desirable to provide a bonus game that can be triggered relatively frequently to maintain player interest, yet provide only a very small chance of awarding the large sums. Such a bonus game should create a high level of excitement and anticipation in the player.